function MyInstanceof(L,R){
    if(typeof L!=='object'||L===null){
        return false
    }


// 输入1 的话V8是执行new Number(1)

 while(L){
  
    if(L.__proto__===R.prototype){
        return true
    }
    L.__proto__=L.__proto__.__proto__
 }
 return false


}
console.log(MyInstanceof([],Array))
console.log(MyInstanceof({},Object))
